1. Field of the Invention
The present invention is directed a door or window that has built-in blinds and more specifically to a blind that is easily removably attachable to the remainder of the frame of the door or window.
2. Background of the Prior Art
Doors and windows incorporating built-in blinds have gained in popularity in the last several years. In these types of systems, a blind is placed between the two panes of glass making up the door or window, the blind capable of being raised and lowered in the usual way. To achieve this construction, two sections of framing, each section holding one pane of glass, are brought together in order to capture the blind therebetween. Typically, the two sections are bolted to one another, often with the bolts visible on an exterior surface of the door or window. Control of the blinds is either manual via pull cords or control rods that pass through the frame so as to be accessible by a user or automatic via an electric motor which is tied into the building's electrical system.
The benefits of such systems lie in the fact that the blind is between the panes and thereby protected. The blinds do not accumulate dust in the manner that blinds attached separate from the window or door so accumulate. Additionally, the blinds are not subject to tearing or crushing from wayward kids and other hazards.
These benefits, are however, tempered with certain drawbacks. In a typical double pane door or window design, the double panes of glass are built as a single unit with the two panes being located in spaced apart relationship to one another with a spacer positioned therebetween around the entire outer periphery of the panes. The spacer is often made from aluminum or vinyl and also has a rubber gasket (often butadiene) along its entire length. In addition to spacing the panes from one another, the spacer acts as a thermal break and the gasket hermetically seals the two panes to one another so as to create dead air space in the cavity between the two panes. This dead space helps the overall door or window achieve greater thermal insulation. The cavity is often filled with a desiccant such as silica sand and an insulating gas such as Argon. The hermetically sealed double pane unit is secured within the remainder of the frame. In a built-in blind door or window, such a hermetic seal cannot be achieved due to the fact that either a manual blind control operator or an electric cord must protrude out from the cavity between the panes, thereby preventing the seal described above. Although the exit point of the control operator or electric cord is provided with appropriate seals, such seals can become less effective over time. In the case of a manual control operator passing through this sealed exit point, the manual control operator passes a physical force through the seal. This physical force acts on the seals which can become less effective over time. In an automatic control configuration, the vibration from the motor acts on the seals that seal the exiting electric cord. Once the seals become sufficiently loose, the Argon gas escapes, not only robbing the door or window of some of its insulating properties, but also allowing a bellowing effect on the panes to increase thereby further reducing the thermal insulating properties of the structure. In the case of interior doors, this tends not to be a problem. However, many of these types of doors and windows are used on the exterior of the building where thermal insulation is a concern.
Another shortcoming of the present double pane built-in blind systems is that in order to change a blind, such as during remodeling, the door or window bearing the blind must be disassembled in order to swap out the blind and thereafter reassembled in order to seal the structure. In order to achieve the maximum thermal insulating capability, including the replacement of the Argon gas into the cavity between the panes, a trained professional using specialized equipment is often needed to accomplish this swap out, which can be very expensive.
What is needed is a built-in blind system for a door or window that allows the panes forming the structure to be hermetically sealed in the usual way in order to achieve a high level of thermal insulation yet allow a building owner to be able to quickly and easily replace blinds without the need to summon a professional window installer. Similarly, a break in a pane should be a relatively easy fix. Ideally, such a system should be of relatively simple design and construction so as to be readily affordable to a large segment of building owners.